Distributed acoustic sensing (DAS) systems use optical fiber as a sensing element. In general, a light source introduces light in the optical fiber, and resulting reflected or scattered light is detected to obtain the acoustic information. Different types of scattered light result when the light is transmitted in the optical fiber. For example, the photons may be elastically scattered in a phenomenon known as Rayleigh scattering. Raman and Brillouin scatter are types of inelastic scatter that also result and are distinguished from Rayleigh scatter and from each other based on their frequency shift. When one or more reflectors (e.g., fiber Bragg gratings (FBGs)) are arranged at one or more portions of the optical fiber, the transmitted light is reflected at a wavelength that is affected by the reflector. The reflected or scattered light may be used to determine parameters such as temperature, strain, and acoustics along the optical fiber.